Do LED lights flicker?

There should be no visible flicker from an LED light in a fitting with a regular switch. If you are experiencing flicker from LED it could be caused by a number of things, including voltage fluctuations in the wiring, or an incompatible dimmer switch. LED lights are not designed to work with most traditional dimmer switches, and should instead have an LED-specific dimmer switch fitted. Using a non-dimmable bulb with a dimmer switch will also cause issues like this.